octave: scripts/general/nextpow2.m annotate

annotate scripts/general/nextpow2.m @ 19788:511b3ae4872b

nextpow2: compute for each element of input instead of its length (bug #44291) * general/nextpow2.m: when input is not a scalar, nextpow2() was using length(x). Not only is this Matlab incompatible, it is also not very useful in the light of nd signals where input will be the length of each dimension. It would also break very bad when the user wants to pass a vector that has length 1 in which case it would use the first element of the vector. This commit changes it so that it computes nextpow2 for each element of the input. When the previous behaviour is intended, `nextpow2 (length (x))' should be used. * NEWS: make note of this backwards incompatible change.

author	Carnë Draug <carandraug@octave.org>
date	Wed, 18 Feb 2015 17:27:06 +0000
parents	4197fc428c7d
children	7503499a252b

rev	line source
19697 4197fc428c7d maint: Update copyright notices for 2015. John W. Eaton <jwe@octave.org> parents: 17744 diff changeset	1 ## Copyright (C) 1995-2015 Kurt Hornik
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	2 ##
3922 38c61cbf086c [project @ 2002-05-01 06:48:35 by jwe] jwe parents: 3426 diff changeset	3 ## This file is part of Octave.
38c61cbf086c [project @ 2002-05-01 06:48:35 by jwe] jwe parents: 3426 diff changeset	4 ##
38c61cbf086c [project @ 2002-05-01 06:48:35 by jwe] jwe parents: 3426 diff changeset	5 ## Octave is free software; you can redistribute it and/or modify it
38c61cbf086c [project @ 2002-05-01 06:48:35 by jwe] jwe parents: 3426 diff changeset	6 ## under the terms of the GNU General Public License as published by
7016 93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6046 diff changeset	7 ## the Free Software Foundation; either version 3 of the License, or (at
93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6046 diff changeset	8 ## your option) any later version.
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	9 ##
3922 38c61cbf086c [project @ 2002-05-01 06:48:35 by jwe] jwe parents: 3426 diff changeset	10 ## Octave is distributed in the hope that it will be useful, but
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	11 ## WITHOUT ANY WARRANTY; without even the implied warranty of
1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	13 ## General Public License for more details.
f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	14 ##
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	15 ## You should have received a copy of the GNU General Public License
7016 93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6046 diff changeset	16 ## along with Octave; see the file COPYING. If not, see
93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6046 diff changeset	17 ## <http://www.gnu.org/licenses/>.
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	18
3321 6923abb04e16 [project @ 1999-10-26 18:15:30 by jwe] jwe parents: 2816 diff changeset	19 ## -- texinfo --
6923abb04e16 [project @ 1999-10-26 18:15:30 by jwe] jwe parents: 2816 diff changeset	20 ## @deftypefn {Function File} {} nextpow2 (@var{x})
19788 511b3ae4872b nextpow2: compute for each element of input instead of its length (bug #44291) Carnë Draug <carandraug@octave.org> parents: 19697 diff changeset	21 ## Compute exponent for smallest power of two larger than input.
511b3ae4872b nextpow2: compute for each element of input instead of its length (bug #44291) Carnë Draug <carandraug@octave.org> parents: 19697 diff changeset	22 ##
511b3ae4872b nextpow2: compute for each element of input instead of its length (bug #44291) Carnë Draug <carandraug@octave.org> parents: 19697 diff changeset	23 ## For each element in the input array @var{x}, returns the first integer
511b3ae4872b nextpow2: compute for each element of input instead of its length (bug #44291) Carnë Draug <carandraug@octave.org> parents: 19697 diff changeset	24 ## @var{n} such that
3321 6923abb04e16 [project @ 1999-10-26 18:15:30 by jwe] jwe parents: 2816 diff changeset	25 ## @tex
9167 1231b1762a9a Simplify TeXinfo and eliminate use of @iftex in arith.txi Rik <rdrider0-list@yahoo.com> parents: 9141 diff changeset	26 ## $2^n \ge \|x\|$.
3321 6923abb04e16 [project @ 1999-10-26 18:15:30 by jwe] jwe parents: 2816 diff changeset	27 ## @end tex
8517 81d6ab3ac93c Allow documentation tobe built for other formats than tex and info sh@sh-laptop parents: 7017 diff changeset	28 ## @ifnottex
10793 be55736a0783 Grammarcheck the documentation from m-files. Rik <octave@nomad.inbox5.com> parents: 9167 diff changeset	29 ## 2^n @geq{} abs (x).
8517 81d6ab3ac93c Allow documentation tobe built for other formats than tex and info sh@sh-laptop parents: 7017 diff changeset	30 ## @end ifnottex
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	31 ##
9141 c1fff751b5a8 Update section 17.1 (Utility Functions) of arith.txi Rik <rdrider0-list@yahoo.com> parents: 8920 diff changeset	32 ## @seealso{pow2, log2}
3321 6923abb04e16 [project @ 1999-10-26 18:15:30 by jwe] jwe parents: 2816 diff changeset	33 ## @end deftypefn
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	34
5428 2a16423e4aa0 [project @ 2005-08-23 18:38:27 by jwe] jwe parents: 5307 diff changeset	35 ## Author: KH <Kurt.Hornik@wu-wien.ac.at>
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	36 ## Created: 7 October 1994
1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	37 ## Adapted-By: jwe
1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	38
1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	39 function n = nextpow2 (x)
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	40
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	41 if (nargin != 1)
6046 34f96dd5441b [project @ 2006-10-10 16:10:25 by jwe] jwe parents: 5642 diff changeset	42 print_usage ();
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	43 endif
1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	44
19788 511b3ae4872b nextpow2: compute for each element of input instead of its length (bug #44291) Carnë Draug <carandraug@octave.org> parents: 19697 diff changeset	45 if (! isnumeric (x))
511b3ae4872b nextpow2: compute for each element of input instead of its length (bug #44291) Carnë Draug <carandraug@octave.org> parents: 19697 diff changeset	46 error ("nextpow2: X must be numeric");
2816 ad4bf2a82b4f [project @ 1997-03-15 21:08:25 by jwe] jwe parents: 2539 diff changeset	47 endif
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	48
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	49 [f, n] = log2 (abs (x));
19788 511b3ae4872b nextpow2: compute for each element of input instead of its length (bug #44291) Carnë Draug <carandraug@octave.org> parents: 19697 diff changeset	50 n(f == 0.5)--;
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	51
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	52 endfunction
12795 9e7ebbaf69ff codesprint: new tests for files in scripts/general directory John W. Eaton <jwe@octave.org> parents: 11523 diff changeset	53
9e7ebbaf69ff codesprint: new tests for files in scripts/general directory John W. Eaton <jwe@octave.org> parents: 11523 diff changeset	54
14363 f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	55 %!assert (nextpow2 (16), 4)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	56 %!assert (nextpow2 (17), 5)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	57 %!assert (nextpow2 (31), 5)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	58 %!assert (nextpow2 (-16), 4)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	59 %!assert (nextpow2 (-17), 5)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	60 %!assert (nextpow2 (-31), 5)
19788 511b3ae4872b nextpow2: compute for each element of input instead of its length (bug #44291) Carnë Draug <carandraug@octave.org> parents: 19697 diff changeset	61 %!assert (nextpow2 (1:17), [0 1 2 2 3 3 3 3 4 4 4 4 4 4 4 4 5])
14363 f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	62
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	63 %!error nexpow2 ()
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	64 %!error nexpow2 (1, 2)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	65

Mercurial > octave

annotate scripts/general/nextpow2.m @ 19788:511b3ae4872b